We’ve been working with John Walker of Texas A&M AgriLife Research and Extension Center to try and sequence goat diets. The question he had for us was whether we could sequence the diets of goats that were browsing in juniper savannas. He sent us a few samples from an experiment where goats were browsing on natural vegetation. In the past they had been using microhistology and near infra-red spectroscopy to get at diet.
When we sequenced the goat fecals he sent us, approximately 75% of the reads were of the juniper OTU. This is higher than his expectation of 40-50% of the biomass intake of the goats being juniper. But, at the time of sampling, juniper has about 50% higher protein than the grasses that make up the rest of the diet. Given that we consider the percentage of the reads from a given species to be proportional to the relative protein intake, this actually matches up well.
There are more details to work through with John, but overall the first sequencing seemed to work well.